add a testcase, from Michael Spencer

llvm-svn: 106026
diff --git a/clang/test/Frontend/preprocessed-output-macro-first-token.c b/clang/test/Frontend/preprocessed-output-macro-first-token.c
new file mode 100644
index 0000000..06b78c2
--- /dev/null
+++ b/clang/test/Frontend/preprocessed-output-macro-first-token.c
@@ -0,0 +1,5 @@
+// This is the first thing other than comments and preprocessor stuff in the
+// file.
+//
+// RUN: %clang_cc1 -fms-extensions -E %s
+#pragma comment(lib, "somelib")